①
LED display
②
7-segment display
③
PLC mode selector switch (toggle switch)
④
Reset button
⑤
Diagnostics button
⑥
NCK commissioning switch (rotary switch)
Figure 4-5
Position of operator control and display elements
4.4.2
LED displays
Meaning of the RUN/STOP, ERROR and MAINT PLC-LEDs
RUN/STOP LED
ERROR LED
MAINT LED
Meaning
LED off
LED off
LED off
Supply voltage at the CPU not present or too low.
LED off
LED flashes red
LED off
An error has occurred.
LED lights up green
LED off
LED off
The CPU is in the RUN operating state.
Description
4.4 Operator control and display elements
NCU 1740
34
Equipment Manual, 10/2021, A5E51087503B AA